Nanoparticles and other nanosized objects are increasingly being used and integrated into numerous applications. Some of these applications include their use as contrast agents for imaging techniques, therapeutic delivery agents, biological labels (e.g., in cancer and other medical diagnostics), industrial fillers and additives, catalysts, and fuel additives.
As the use of nanoparticles continues to become more widespread, there is a growing need to monitor the transport and fate of these nanomaterials as they are increasingly released into the environment upon disposal. Attempts to track nanomaterials, particularly over lengthy time periods (e.g., months or years), has been hampered by several difficulties. In particular, the conventional method of labeling the surface of nanoparticles with an observable marker is highly susceptible to loss of the marker upon prolonged exposure of the nanoparticle to a degradative environment.